连续消毒对水中大肠杆菌抗力曩探讨

Under defined conditions E. coli were subjected to repeated chlorine disinfections 10 times. The survival E. coli at 30 s (A10), and the survival E. coli at 10 min (B10) had no difference in resistance to chlorine to their original strain (A0). However, the compound E. coli (C10) survived at various contact time showed an increased resistance than their original strain (A10), the degree of increased resistance varying with different conditions of disinfection. E. coli C1(0) lost its increased resistance after it has been passaged 10 times on nutrient agar.     

检测莱姆病McAb-ELISA竞争法的建立及初步应用

用自制的莱姆病单克隆抗体VLG2 F9株,建立了检测血清中莱姆病抗体的ELISA非限制性竞争法。用超声波粉碎、高速离心相结合制备可溶性抗原;用羟基磷灰石层析法对单克隆抗体进行纯化均获得了满意结果。实验结果表明,ELISA竞争法特异性高、稳定性和可重复性好,操作简便,可用于不同种动物血清的检测,用该方法检测92份人血清阳性率22.8％,同时测定101份牛血清阳性率为69.9％,该法用于莱姆病的实验诊断尚属首次。该法的建立对莱姆病实验诊断的标准化以及流行病学调查具有重要的实际意义。     

抗MS_2多聚酶单克隆抗体的制备及鉴定

应用MS_2-X蛋白(含MS_2多聚酶的98个氨基酸,乙型肝炎X抗原的145个氨基酸)免疫小鼠,取其脾细胞与Sp2/0细胞融合后,经阳性克隆检测,克隆化及体外传代培养,共筛选出了2株抗MS_2多聚酶的单克隆抗体,这在国内尚未见报道。经ELISA及Western Blot实验证实,此2株单克隆抗体只能与MS_2多聚酶发生反应,而不能与乙型肝炎X抗原和正常细菌蛋白发生反应,其抗体亚类为IgG_1,腹水效价为1∶32000～1∶64000。应用抗MS_2单克隆抗体,可以建立亲和层析技术,高效快速地将基因工程表达的MS_2多聚酶—目的蛋白融合蛋白,从大量的细菌蛋白中纯化出来,这对深入研究目的蛋白的结构与功能具有十分重要的作用。     

抗HBx IgM的检测及临床应用

利用羊抗人IgM,基因工程表达的乙型肝炎X抗原和酶标抗-HBx单克隆抗体,建立了检测血清中抗-HBx IgM充体的ELISA双夹心法,并进行了初步应用。实验结果表明,此方法的特异性强,稳定性及重复性好(批内变异系数8.64％,批间变异系数10.60％,重复率为100％),且不受血清中抗-HBc IgM、抗-HAV IgM及类风湿因子的影响。由于目前国内外都没有抗-HBx IgM标准品,故对方法的敏感性没有报道。     

连续消毒对水中指标病毒—f2噬菌体抗力影响探讨

Under defined conditions, E. coli bacteriophage f2 was subject to repeated disinfection by chlorine 10 times. The survival bacteriophage f2 was compared with its original strain in resistance to chlorine. Experimental results showed that bacteriophage f2 increased its resistance after chlorine disinfection. The increased resistance varied under different conditions. The higher the pH, the greater the increased resistance. The survival bacteriophage f2 maintained its increased resistance though it was passaged 10 times in nutrient broth. The reason for the increased resistance of bacteriophage f2 after chlorine disinfection was probably the chlorine-induced mutation or spontaneous chlorine-resistant mutation.